To achieve their full potential, networks must be secure as well as functional. With this in mind, the author identifies metrics designed to mitigate vulnerabilities to cyberattacks in networks that are key to the critical infrastructure of the US. He discusses both growth metrics — based on data obtained from the US National Institute of Standards and Technology and Department of Homeland Security vulnerability database — and metrics designed to mitigate the risk of security vulnerabilities in networks. If used together, these two types of metrics can help make networks more secure.